Secondary air systems are utilized in vehicles to add oxygen to exhaust gases. Typically, secondary air systems operate by pumping fresh air into the exhaust by a simple electrical or mechanical air pump. In some vehicles, the secondary air system is generally used only at startup to help burn the rich air-to-fuel mixture needed to run a cold engine. Once the catalytic converter is at operational temperature, the secondary air system is shut down.
Secondary air systems are effective at reducing cold-start vehicle emissions. However, such conventional secondary air systems include multiple separate components such as a separate sensor, air pump, and check valve, which adds increased cost and complexity to the vehicle. Accordingly, while such conventional secondary air systems work for their intended purpose, it is desirable to provide an improved secondary air system.